F_Quites; Reintegration Through User Acknowledgement With F_Quites - Siemens SIMATIC S7 F Manual

Fail-Safe Blocks
8.4.10

F_QUITES

Function
This block enables fail-safe acknowledgment from a non-fail-safe ES/OS. This
allows reintegration of F-I/Os to be controlled via the ES/OS, for example. An
acknowledgment comprises two steps:
1. Changing the input IN to the value 6
2. Changing the input IN from the value 6 to the value 9 within a minute
The block evaluates whether, after the input IN has changed to the value 6 after a
second at the earliest or a minute at the latest, a change to the value 9 has
taken place. The signal 1 is then output at the output OUT (output for
acknowledgment) for the duration of a single cycle.
If an invalid value is entered or if the change to 9 does not take place within a
minute or before a second has elapsed, the input IN is reset to 0 and the two steps
specified above have to be carried out again.
During the time in which the change from 6 to 9 must occur, the non-fail-safe
output Q is set to 1. As soon as the input IN has accepted the value 9, or if there
has not been a change within a minute, Q is reset to 0.
Note
Because the fail-safe output OUT is only set for one cycle, a separate F_QUITES
is required for each cyclic interrupt.
If there is only one block for different run-time groups in a cyclic interrupt, the
blocks F_S_BO and F_R_BO must be used for the exchange of data between the
run-time groups.
Safety Note – Reintegration through User Acknowledgement with F_QUITES
!
The non-safety-related input IN must not be interconnected with a signal or defined
by a signal that automatically produces the above mentioned condition (change
from 6 to 9 within a minute) for a fail-safe acknowledgment. The fail-safe
acknowledgment can only be produced by means of conscious, manual input on
the ES/OS, not automatically in the program.
Changing the Overall Signature of the Offline Safety Program
If the above two acknowledgment steps are entered directly via the ES in CFC test
mode rather than via the OS, the overall signature of the offline Safety Program
changes as a result of the acknowledgment. To avoid this, you must ensure that a
zero is entered after a 9 or an invalid value.
Fail-Safe Systems
A5E00085588-03
8-45